Air conditioning or cooling system



Feb. 29, 1944. -r w. CARRAWAY AIR COfiDITIONII IG OR COOLING SYSTEM Filed March 31, 1941 6 Sheets-Sheet 1 1 INVENTOR. 0 m4 @a uzaw BY .v

Feb. 29, 1944. r. w. CARRAWAY I 2,342,841

AIR CONDITIONING OR'COOLING SYSTEM INVENTOR. ago/w'sa aa lant/wag}, I

Feb. 29, 1944.

T. w. CARRAWAY AIR CONDITIONING OR COOLING SYSTEM 6 Sheets-Sheet 3 Filed March 31, 1941 m m a a w W IIIIIIIIIII. r V .r I I I I I I I I I I I I I I I I I I I I I I l I I I I I I l I I I I I Feb. 29, 1944. T; w, CARRAWAY 2,342,841

AIR CONDITIONING OR COOLING SYSTEM Filed March 31, ,1941 6 Sheets-Sheet 4 4rranmtrs 1941 s Sheets-She et 5 i-G OR COOLING SYSTEM 1944 T w. CARRAWAY AIR CONE JTIQN? Flled Mann A wilful INVENTOR. o wwva 9 0: @amawav),

Pltented Feb 29,1944 I UNITED STATES PATENT OFFICE y AIR connrrronnz firi zoonmd svs'rsmr Thomas W. Cari-away, Dallas, Tex. Application Mai-en 31, 1941, Serial No. ssauo (c1, ass-44) 'io'ciaims.

This invention relates to air conditioning or cooling systems and more particularly to such systems in which air cooling is effected by evaporation of water or other suitable evaporative liquid.

The cooling of air by evaporation of liquid in contact with the air is well knownand there have been numerous installations of 'cooling equipment operating upon this principle. Many of the prior installations, and numerous proposals as to other installations, included rather complex and expensive equipment for refrigerating water used as the evaporative liquid, for reheating the air after cooling'for dehumidiflcation, and for otherwise providing very close thermal and humidity control. Such equipment may be desirable from the standpoint of providing extremely close control but is far too expensive to permit its being used in domestic or other installations in which the often doubtful advantage of extremely close control is not worth the large additional expense of achieving it;

the frequent undue over-humidiflcation of the air resulting in its feeling, clammy and uncomfortable to persons in the conditioned area or en-' closure. 1

An object of the present invention is to provide an air cooling unit of the evaporative liquid cooling class in which the liquid is presented to the air stream in such manner as to provide for efficient cooling of the air by evaporation.

invention and with the controls therefor shown diagrammatically;

Figure 4 is a transverse vertical sectional view takenonthe linel-lof Figure 3;

"Figure 5 is a longitudinal sectional view of still further form of unit constructed in accordanoe with'the invention and showing the controls therefor diagrammatically;

Figure 6 is a transverse vertical thelineO-tofFigureii;

Figure '1 is aside elevation of a further form of unit embodying the invention with some parts broken away and other parts shown in section;

Figure '1 is a schematic view of an air cooling apparatus including a unit of the kind shown in Figure:

Figure 8 is a front elevation of the unit shown in Figure 7 with some parts broken away and section on others shown in section, and showing controls I diagrammatically; and;

Figure 9 is a diagrammatic view of a buildin with a unit of the kind-shown in Figures 1 and 2 arranged therein for conditioning air. i

In the embodiment shown in Figures 1 and 2. a duct or casing, I, supported on legs I, is provided with a blower 3 driven from a motor 4 by a belt I, the arrangement being such that the blower draws air through the duct I and discharges it conditioned 0 Another object is to provide means for controlling the blower and liquid supplying means of an evaporative liquid type air cooler which, though flexible and adapted to eflect eilicient control under varying" air conditions, is simple and inexpensive.

Other objects will become apparent from a reading of the following detailed description,

through an-opening 8 to the enclosure to be conditioned. Air enters the casing I through a fresh air inlet I arranged to communicate with the outside and also through a return air inlet 8 adapted ,to receive air from the enclosure being It is desirable to provide a flow of substantially all fresh air under normal conditions, but at certain times atmospheric conditions require that the inflow of fresh or outside air be cut oil and air from the conditioned area be recirculated through the cooling apparatus. For controlling the kind of intake air a damper t is pivoted as at II at the point of convergence of the inlet openings I and i remote from the discharge end ottheduct.

In order to remove the impurities, such as dust, pollen, and other foreign matter, a filter II is positioned transversely 01'- the casing l adjacent its inlet end. The filter may comprise a matlike mass of excelsior, glass wool or any other suitable air pervious filtering structure. ,The air flowing inthe direction of the arrows a and after passing through the filter H enters a cooling chamber I! in which is mounted a plurality of spray nozzles II from which water or other suitv able evaporative llquidis sprayed for cooling the orative ll air by evaporation in accordance with well known principles. After passing through the cooling chamber I! the air moves through a baille H which acts to eliminate from the air stream any suspended moisture particles which have not been completed evaporated. The battle H may also be formed as a mat of excelsior, glass wool, or other suitable or known material.

Water, or other evaporative fluid, is delivered to the spray nozzles l3 through a feed pipe I! receiving the fluid under pressure from the pump l8 driven by a motor [1. The water supply may be maintained in a sump or reservoir it which is connected to the intake side of the pump by a pipe l9. Preferably, water is maintained at a predetermined ievel in the reservoir or sump It by means of an inlet pipe 20, the flow of water through which is controlled by a float valve 2| which may be of any suitable or conventional form.

In operation, the inlet air, comprising fresh air entering through the opening '1, passes through the filter ii which removes foreign matter from the air stream and thence the air passes into the cooling chamber I! where it is cooled by evaporation of Water or other evaporative fluid sprayed into the chamber through the nozzles IS. The cooled air then passes through the baiile H which removes any entrained liquid particles and thenis deliveres through the discharge opening 8 to the area or enclosure being conditioned. This form. of oil." cooler is well adapted for use where the water or other evaporative liquid available is substantially free from foreign matter and does not tend to deposit a scale which would clog the nozzles Novel and improved any very flexible means are provided for controlling the blower, the evapand the damper 9, in accordance u vary lg conditions. The blower is normally controlled a thermostat 22 located in the con ome area the pump normally is controller i'y a ho. ostat 23 located in the conditionecl. it atively operable manual controls are provided for obtaining the best re suits for providing human comfort under special or unusual atmospheric conditions. In the wiring arrangement, shown diagrammatically, electrical power is supplied to the main line conductors 24 and i whlchiead to the inlet side oi'a master cut-off switch 28. The other sid of the switch 28 has connected to it conductors 21' and 28.

. The conductor 28 leads to one side oi the blower motor I and the conductor 21 leads through the thermostat 22 and a conductor 29 to the other side of the motor 4. A manually operable switch III is adapted to be hunted across the thermotat 22 for completing the motor circuit irrespective of the temperature within the conditioned area under special conditions which'may make this desirable.

One side of th humidostat 28 is connected by a conductor 3| to a conductor 32 which in turn leads to the conductor 28. The conductor II also is connected to a conductor 83 which leads to one contact or a single pole double-throw switch M. The other side 0! the humidostat leads through a conductor 35 to the other contact 01' the switch 34. The middle or blade contact 0! the switch 34 leads through a conductor II to one side of the pump motor H. The other side i the pump motor leads through a conductor 81 to the condoctor 29 which, as previously stated, leads through the thermostat 22 (or the manually operable switch 30) to the conductor 21 and thence to the master switch 26.

Assuming that normal summer conditions prevvail, i. e.; during the day time and with reasonably dry and warm outside air, the apparatus will be conditioned for normal operation by having the damper 8 set in the position shown in full lines in Figure 1 and by closing the master switch 28, opening the manually operable switch 30, and closing the blade of the switch 34 on the contact connected to the conductor 35. If the temperature of the conditioned area rises above a predetermined temperature for which the thermostat 22 has been set, the thermostat will respend to close the circuit to the blower motor 4 so as to operate the blower and draw fresh air through the inlet 1 and the cooling chamber l2 and deliver it to the area being conditioned. Assuming also that the humidity 01' the air in the conditioned area is not above a predetermined value, the humidostat 23 will be in condition for closing the circuit through the pump motor I! so as to drive the pump I8 and deliver evaporative liquid through the spray nozzles l3. It will be observed that the pump motor I! cannot operate unless the blower motor also is operating. When the temperature in the conditioned enclosure has been lowered to a predetermined value for which the therrno at is set, the thermostat will respond to open the circuits to both the blower motor 4 and the thereby stopping the blower the delivery 01 evaporative 'l to the spray nonzles. However, if the humidity in the area being conditioned should rise to a predetermined upper limit before the 'ature has dropped to the desired value the h" stat 23 will open to break the circuit to 3 p motor ll only, so as to discontinue the delivery oi the evaporai'luicl to the spray noel-lies iii without, however, stopping the blower. In some instances it may advantageous to cool the conditioned area empcrature lower than at which the thermos normally would discontinue operation oi cooling unit. For example, if in the morning lb i anticipated that the day will become unusually not later on, the manually operable switch 3% may be closed so as to shunt the thermostat and maintain the cooling unit in operation so as to reduce the temperature of the conditioned area to a level lower than that usually maintained heiore the unit becomes subjected to the heavy load of maintaining the conditioned area cool when the outside temperature is abnormally high. I

Under some conditions it may be desirable to I operate the blower without supplying evaporative liquid to the spray nozzles N. For example, it may be assumed that a store or barber shop is opened at an early morning hour and it is .de-

period as is necessary to properly condition the enclosure.

If, during the middle of the day, it is very hot and dry, improved cooling results may be obtained by placing the pump motor ll, as well as the blower motor 4, under the control of the means which normally controls the blower motor 4. To effect such control the blade of the switch 34 is closed upon the contact leading to the condoctor 33 whereby the pump motor l1 will be operated to effect delivery of evaporative fluid to the nozzles I 3 whenever the blower motor 4 is running, irrespective of whether the blower motor is controlled by the thermostat 22 or the manually operable switch It.

Under normal conditions the damper 8 is in position to leave the fresh air inlet I fully open,

as shown in full lines in Figure 1, but under some conditions it is desirable to cut off the supply of fresh air and to cause return air to be delivered to the cooling chamber. Preferably the damper is adapted to be moved so as substantially to shut oil! the supply of fresh or outside air by means of a damper operating motor 38 which may be of conventional form and which is adapted to move the damper 8 through an operating connection 39. For controlling the motor 38 and moving the damper 9 automatically in dependence upon outside atmospheric conditions, a

humidostat 40is connected by a conductor through a switch 42 to the supply line 21. Another,conductor 43 leads from the humidostat return air inlet 5.4, the relative amounts of fresh to the damper motor 38 and a third conductor for example, as a result of rain or fog,'the humideliminated. When the outside air becomes more normal as to its humidity content the humidostat 40 will respond to cause the damper 9 to be returned to its normal position so as to provide for the desired inflow of fresh outside air. If for any reason it is desired to leave the damper in set position this may be accomplished by opening the manually operable switch 42 which will disable the humidostat and render it ineflective for controlling the damper 9.

Special conditions may require that the damp er 9' be moved to or maintained in a position other than that to which it would bemoved or in which it would be maintained by the humidostat 40. For this reason a manually operable single pole double-throw switch 46 is provided, the blade of the switch being connected through the conductor 41 to the supply line 21. Conducsuch as the spray nozzles shown in Figures 1 and 2. Even if the supply of liquid is filtered to remove suspended foreign matter, the liquid still may contain substances in solution which deposit out as scale and eventually clog. the nozzles.

, Figures 3 and 4 illustrate an embodiment of the invention particularly suited for use in localities 'inwhich the easily available evaporative liquid is not suitable for use in units equipped with spray nozzles. The unit shown in Figures '3 and 4 includes a duct or casing 50 through which air is moved in the direction of the arrows b by means of a blower 5| drivingly connected to a motor by a belt 53. Air moved through the casing after being cooled is delivered through a discharge opening 54 to the area or enclosure to be conditioned. The interior of the casing 5i communicates with a fresh air inlet 55 and a air and return air admitted to the casing being controlled by a damper 51 pivoted as at 58. The inlet air passes through. a filter 59 for removing suspended foreign matter, thence through anopen chamber portion and then through a mat 80 of excelsior, steel wool, glass wool or any other suitable mat of air pervious material formed with multitudinous air spaces or passages. In accordance with the invention. the mat 60 is maintained wet so as to provide multitudinous liquid films adjacent the numerous air passages and in contact I with the air sons to be available for cooling the air by evaporation. A pump 6| is adapted to receive evaporative liquid from a sump or reservoir 62 in which liquid is maintained at a predetermined level by means of a supplyv pipe 28 controlled by a float valve 64, of conventional form.

, The pump is driven by a motor 85 to deliver fluid through a pipe which communicates'with a horizontal header 61 extending across the top of the mat 60 and being perforated so as to provide for the free flow of liquid into the top of the mat.

In operation, liquid supplied through the pipe i6 is delivered by the header 61 to the top of the mat and trickles down throughthe. mat so as to cover each thread .or portion thereof with a film of moisture which thereby is presented for contact with and evaporation by the stream of air passing through the casing 50 whereby the air; is cooled by evaporation before being delivered to the conditioned area. a

The means for controlling the operation of the blower motor 52, the pump motor 65, and the damper 51 may be thesame as the means for controlling the blower motor 4, the pump motor l'|,,and the damper 9 in the construction shown in Figures 1 and 2. Consequently, the means for controlling the apparatus shown in Figures 3 and 4 will not be described in detail. Parts of the control means shown in Figures 3 and 4 are designated by reference characters the same as those which designate the corresponding parts shown in Figures 1 and 2.

tors 4! and 49 lead respectively from theswitch contacts to the damper control motor 3|. By

closing the switch blade selectively upon the con tacts associated with the conductors 48 and 49,

the damper may be moved to any' desired position to suit existing'conditions.

, In some localities it is diflicult or expensive to I provide a supp y of water or other evaporative liquid which will not tend to-clog spray nozzles,

Figures 5 and 6 show another form of unit especially suited for use in localities in which area or enclosure to be conditioned. A fresh air inlet opening 13. provides for the admission of outside air or return air may be drawn through 4 4- asaaeu cooled by evaporation in a manner to be described and thence passed outwardly through the discharge opening 12. Water or other suitable evaporative fluid is maintained at a predetermined level in a sump or reservoir 18' in the bottom of the cooling chamber 18, the fluid being admitted through a supply pipe 1! controlled by a conventional float valve 80.

A cylinder 8|, formed of wire mesh or other suitable open structure, is carried by spiders 82 keyed to a shaft 82" journaled as at 83 within the cooling chamber. A cylindrical mat-like body of excelsior, steel wool, glass wool, or other material having multitudinous air passages, is carried by the open work cylinder 81 and is arranged to dip into the liquid in the sump or reservoir 18. The cylinder is adapted to be rotated slowly through driving means comprising a. pulley I! connected by a belt 88 to a pulley 8'! of a reduction gear assembly 81! connected by a belt 81 to a pulley 81 on a motor 88. In operation the cylinder ll turns slowly when it is desired to present fllms of moisture in the path of the air stream for cooling by evaporation. As the mat material 84 passes throughthe liquid in the res- 0 ervoir 18 it picks up liquid and carries it transversely through the air stream moving through the cooling chamber. The moisture doesnot have to be delivered through any small openings or orifices susceptible to becoming clogged by foreign particles or deposited scale. The means for controlling the operation of the blower 68 and moisture supplying means 84 are the same as the control means shown in connection with the apparatus illustratedin Figures 1 and 2 and need to not be described again in detail. The several parts of the control means shown in Figure 5 are designated by reference characters the same as. those which designate corresponding control parts shown in Figure l.

Figures 7, '1- and 8 show a modified form of unit which has been found particularly effective in climates which are customarily dry as well as hot. Under these conditions it is desirable to provide for as large an amount of evaporation as possible in order to eifect the necessary cooling. The apparatus shown in Figures 7. 'I and i! is capable of taking advantage of, the dry air for effecting maximum cooling and 'at'the same time is compact and therefore adapted to' be fitted within a small space so often. necessary in domestic installations. The air to be cooled is moved in the direction of the arrows d through a duct or casing 8| containing the cooling unit and is discharged through an opening 00 com- .0

municating with the area or enclosure to be cooled. Fresh air from the outside may enter through an inlet opening II or return air may be admitted through an opening 02, a damper 03 being provided for controlling the fresh air and return air admitted to the cooling unit.

The cooling unit generally designated 94 is adapted to, be housed entirely within the duct or casing II. The unit comprises four sides, I,

u, n and a, three sides, a, n and as. of which comprise mats 98', l1 and OI, respectively, of excelsior, steel wool, glasswool, or similar material, whereas the side 95 may be imperforate. A blower ll, located within the four sides of the housing, is driven from a motor I" by means of a belt Ill. Evaporative liquid is maintained at a predetermined level in a sump or reservoir I02 by means of a supply pipe I controlled by a conventional float valve IN. A pump I", driven by a motor I", delivers fluid from the sump to a pipe 101 and thence to horizontal delivery pipes or headers l6, ll and SI" respectively over? lying the tops of the mats O8, 81- and 9". In operation, air drawn through the casing 89 has to pass through the'rnats 8'', l1 and 08' which are maintained wet with multitudinous films of evaporative liquid which, through evaporation, cool the air before it passes out through the discharge opening The means for controlling the blower 99 and. evaporative liquid supplying means is similar to the control means described in connection with the form shown in Figure 1 with the exception that for controlling the apparatus shown in Figures 7 and 8 a clock switch I08 is interposed in the conductor 38 and is so adjusted as to prevent operation of the evaporative liquid supplying means during certain predetermined hours. For example, it may be advantageous to automatically disable the water supplying means during the night so as to allow the blower to operate as a ventilating system drawing in outside air which is cleansed by the filtering action of the mats 96, 11- and 88 and delivered into the conditioned enclosure without lowering the temperature by evaporation. At a predetermined time in the morning the clock will automatically place the liquid supplying means back under the control 0! the humidostat and the thermostat so as to provide for cooling by evaporation when conditions in the conditioned enclosure require it.

Figure 9 shows diagrammatically a house installation of a unit of the kind shown in Figures l. and 2. The other units described, however,

may be similarly installed in a house and good results obtained. The house is shown as including an upper attic enclosure I" and two lower room enclosures iii and Ill. The cooling unit is 5 installed with its discharge opening 0 arranged so as to deliver divided air streamsat l and i respectively into the rooms Ill and III at their ceiling level. Fresh air from the outside is drawn in through the inlet opening I. Return air from the room Ill passes through a passage III near the floor into the room Ill and the return air from both rooms I" and Ill passes up through the return air passage III which. communicates with the attic Ill, it being noted, however, that is the passage III does not have direct or closed communication with the air cooling unit. Return air, after passing through the passage H8, has to move through the attic space II! as indicated by the arrows e. Thus the return air. after leaving the conditioned enclosure, moves through the attic and out through a wall outlet Ill, instead of being discharged directly outside the conditioned enclosure and coolsthe attic, maintaining the ceilings of the conditioned rooms cool. through the attic, overheating of the attic, which normally would be excessive during hot summer days, is prevented and the resultant maintenance of cool ceiling of the rooms below adds greatly to the comfort of occupants of the conditioned rooms. Return air enters through the opening I only when the damper I is moved to close or partially close the fresh air inlet '1 and this takes By moving a large volume of cool air from the invention as defined in the claims. For

example, it is apparent that a solenoid-operated valve controlling a flow of fluid to the fluid film dispersion means may be employed instead of a motor driven pump as disclosed herein.

I claim:

1. In an air conditioning system, an enclosure to which cooled air is to be delivered; a conditioning chamber having an inlet and having-an outlet arranged to discharge cooled air to said enclosure; a blower for moving air through said chamber, and to said enclosure; means for sup plying liquid within said chamber to effect evaporative cooling of air passing therethrough; a thermostat responsive to temperature in said enclosure for controlling operation of said blower and said liquid-supplying means; and manually operable means for controlling operation of said blower and said liquid-supplying means independently of said thermostat.

2. In an air conditioning system, an enclosure to whichcooled air is to be delivered; a conditioning chamber having an inlet and having an outlet arranged to discharge cooled air to said enclosure; a blower for moving air through said chamber and to said enclosure; means for supplying liquid within said chamber to effect evaporative cooling of air passing therethrough; a thermostat responsive to temperature in said enclosure for controlling operation of said blower and said liquid-supplying means; manually operable means for controlling operation of said blower and said liquid-supplying means independently of said thermostat; and a humidostat responsive to the humidity in said enclosure for controlling said liquid-supplying means conjointly with the means controlling the blower.

3. In an air conditioning system, an enclo-- enclosure for controlling operation of said blower and said liquid-supplying means; manually operable means for controlling operation of said blower and said liquid-supplying means independently of said thermostat; a humidostat responsive to the humidity in said enclosure for controlling said liquid-supplying means con- Jointly with the means controlling the blower;

and a selector device for selectively placing the a humidostat responsive to humidity in said enclosure; and a selector device for selectively placing said liquid-supplying means under conjoint control of said blower control means and said humidostat or under control of said-blower controlling means independently of said humidostat.

5. In an air conditioning system, an enclosure to which conditioned air is to be delivered; a duct for delivering conditioned air to said enclosure; means including a discharge opening for moving air through said duct and discharging conditioned air to said enclosure; a fresh air inlet communicating with air outside said enclosure and being adapted to communicate with through; and means constituting the sole atmospheric condition responsive means for controlling, operation of said damper comprising a humidostat responsive to a predetermined high humidity of the fresh air for effecting operation of said damper to restrict the innow of fresh air to a minimum, and responsiveto humidity below said predetermined high humidity for effecting operation of said damper to provide for a normal inflow of fresh air.

6. In an air conditioning system, an enclosure to which conditioned air is to be delivered; a duct for delivering conditioned air to said enclosure; means including a discharge opening for moving air through said duct and discharging conditioned air to said enclosure; a fresh air in- I let communicating with air outside said enclosure and being adapted to communicate with said with said duct; a damper for controlling the fresh air and return air entering the duct; a humidostat responsive to a predetermined high humidity of the fresh air for eflecting operation of said damper to restrict the inflow of fresh air to a minimum, and responsive to humidity below said predetermined high humidity for effecting operation of said damper to provide for a normal inflow of fresh air; and means operable independently of said humidostat for efiecting operation of said damper to restrict inflow of fresh air to a minimum or to provide for a normal inflow of fresh air.

7. In an air conditioning system, an enclosure to which conditioned air is to be delivered; a duct for delivering conditioned air to said enclosure; means including a discharge opening for moving air through said duct and discharging conditioned air to said enclosure; a fresh air liquid-supplying means under the conjoint con trol of the blower controlling means and said humidos'tat, or under the control of the blower controlling means independently of said humidostat.

4. In an air conditioning system, an enclosure to which cooled air is to be delivered; a conditioning chamber having an inlet and having an means for controlling operation of said blower;

inlet' communicating with air outside said enclosure and being adapted to communicate with said duct, a return air inlet communicating withsaid enclosure and being adapted to communicate with saidduct; a damper for controlling the fresh air and return air entering the duct;

means for supplying liquid within said duct to effect evaporative cooling of air passing therethrough; and means constituting the sole atmospheric condition responsive means for controlling operation of said damper comprising a humidoveration of said damper to provide for a normal inflow of fresh air; means for rendering said humidostat ineffective for controlling operation of said damper; and damper operation controlling means operable independently of said humidostat and irrespective of whether or not said humidostat is conditioned to be effective for controlling operation of said damper.

8. In an air conditioning system, an enclosure to which cooled air is to be delivered; a conditioning chamber having an outlet arranged to discharge cooled air to said enclosure; a fresh air inlet communicating with air outside said enclosure and being adapted to communicate with said chamber; a return air inlet communicating with said enclosure and being adapted to communicate with said chamber; a damper for controlling the fresh air and return air entering the chamber; a blower for moving air through said chamber; means for supplying liquid within said chamber to effect evaporative cooling of air passing therethrough; a thermostat responsive to temperature in said enclosure for controlling operation of said blower; manually operable means for controlling operation of said blower independently of said thermostat; a humidostat responsive to humidity in said enclosure; means for selectively conditioning the liquid supplying means to be completely inoperative, or to be operative under the control of the blower controlling means, or to be operative under the joint control of the blower controlling means and the humidostat; a second humidostat responsive to a predetermined high humidity of the fresh air for effecting operation of said damper to restrict the inflow of fresh air to a minimum and responsive to humidity below said predetermined high humidity effecting operation of said damper to provide for a normal inflow of fresh air, means for rendering said second humidostat ineffective for controlling operation of said damper; and damper operation controlling means operable independently of said second humidostat and irrespective oi-whether or not said second humidostat is conditioned to be eil'ective for controlling operation of said damper.

9. In an air conditioning system, an enclosure to which cooled air is to be delivered; a conditioning chamber having an inlet and having an outlet arranged to discharge cooled air to said enclosure; a blower for moving air through said chamber and to said enclosure: means for supplying liquid within saidchamber to effect evaporative cooling of air passing therethrough; a thermostat responsive to temperature in said enclosure for controlling operation of said blower and said liquid-supplying means; and clock controlled means for rendering said liquid-supplying means ineil'ective during predetermined periods irrespective of response of said thermostat to temperature changes. 7

10. In an air conditioning system, an enclosure to which cooledair is to be delivered; a conditioning chamber having an inlet and having an outlet arranged to discharge cooled air to said enclosure; a blower for moving air through said chamber and to said enclosure; means lor supplying liquid within said chamber to effect evaporative cooling of air passing therethrough: a thermostat responsive to temperature in said enclosure for controlling operation of said blower and said liquid-supplying means; manually operable means for controlling operation of said THOMAS W. CARRAWAY. 

